The invention is based on a pressure generator for a hydraulic vehicle brake system as defined hereinafter. Such a pressure generator is already known from German Offenlegungsschrift 32 36 366; in it, a piston displaceable longitudinally counter to spring force, is received at the cylinder. The resiliently supported actuating element of the seat valve is located inside the piston. The actuating force for the pressure generator is generated by an electromagnet, which because of the relatively large piston cross section and short stroke must generate a strong armature force so that a sufficiently strong braking force will be available for traction control. This necessitates using a large and therefore heavy electromagnet, yet such a magnet reacts relatively sluggishly, so the traction control apparatus is unable to follow up changes in wheel rotation except after some delay. This greatly lessens the control quality of the brake system.